As for such a relay, there is known, e.g., a remote control relay (see, e.g., Japanese Unexamined Patent Application Publication No. 2011-249137).
In the remote control relay disclosed in Japanese Unexamined Patent Application Publication No. 2011-249137, there is accommodated in a case an electromagnetic device having a plunger moving reciprocally by power supply to a coil and an opening/closing mechanism for switching on/off of a contact part in response to the reciprocating movement of the plunger.
The electromagnetic device includes a coil, a coil bobbin, a plunger, two armatures, a yoke, a residual plate, two permanent magnets, and two auxiliary yokes.
The coil bobbin has a cylindrical tubular body around which a coil is wound, plate-shaped flanges provided at both end portions in an axial direction of the tubular body, and side pieces protruding from both edges of each of the flanges in a direction opposite to the tubular body.
The remote control relay disclosed in Japanese unexamined Patent Application Publication No. 2011-249137 is disadvantageous in that it is difficult for the armature provided between the two side pieces protruding in the same direction from the flange of the coil bobbin to move smoothly due to large friction between the two side pieces and the armature moving along the axial direction of the coil bobbin.